This study will look at changes in pig lung associated with copper deficiency and also changes associated with copper deficient animals that have been supplemented with zinc. A marked deficiency in elastic tissue has been noted in animals on the zinc supplementation. The compliance of these lunds are altered significantly. We will raise a number of pigs on the modified diets. We will evaluate their pulmonary function under anesthesia, and after exsanguination the lungs will be removed for pressure volume studies and for biochemical studies of elastic tissue as well as evaluation of morphology. Through this study we wish to better define the role of elastic tissues in the function of the normal lung. We also wish to determine if the copper deficient zinc supplemented pig is a reasonable large animal model of altered pulmonary physiology resembling emphysema. We also wish to determine the degree of elastolysis in this copper deficient zinc supplemented lesion. The methods to be utilized are; measurement of pulmonary resistance, dynamic compliance, quasistatic pressure volume curves, lung volume measurements, carbon monoxide diffusing capacity, nitrogen clearance delay, and lung clearance index. Also, after death, we will measure delay, and lung clearance index. Also, after death, we will measure air static pressure volume relationships both with room air and with saline. Quantitative and qualitative measurements of elastic tissue will be performed in parenchyma, blood vessels and bronchi through the use of amino acid analyses. Elastic tissue integrity will be achieved through quantitative NH2 terminal amino acid evaluation. Histologic studies will serve as internal controls on all animals.